Patents by Inventor Volkmar W. Leistner

Volkmar W. Leistner has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5863164
    Abstract: A Tee-nut with flareable portion comprises a flange head, a plurality of prongs extending from the flange head, and a hollow barrel extending from the flange head. The hollow barrel has an internally threaded portion provided at one end of the barrel connecting to the flange head, and an enlarged flareable portion extending from the internally threaded portion and provided at a free end of the barrel. The end of the enlarged flareable portion is radiussed inwardly so as to form an end opening having a diameter which reduced in relation to the diameter of the flareable portion to facilitate insertion into a hole in a workpiece. The present invention further discloses a workpiece fitted with such a Tee-nut.
    Type: Grant
    Filed: January 23, 1998
    Date of Patent: January 26, 1999
    Assignee: Sigma Tool & Machine
    Inventor: Volkmar W. Leistner
  • Patent number: 5722131
    Abstract: A furniture clip of the type used with furniture springs, having wire frames, and in which such furniture clips furniture clips are used for attaching the wire frames to furniture, and having a sheet metal member defining length and width, and formed transversely with a wire receiving recess, and two panels extending at an acute angle relative to one another on either side of the recess, a shield of flexible thermoplastic material extending over the inner surfaces of the two panels, and extending around said wire recess, and edge portions of the thermoplastic defining a width greater than the width of the sheet metal.
    Type: Grant
    Filed: July 25, 1995
    Date of Patent: March 3, 1998
    Assignee: Sigma Tool & Machine
    Inventors: Volkmar W. Leistner, Garry Randall Olson
  • Patent number: 5618144
    Abstract: A tee-nut comprises a flange head, a plurality of prongs extending from the flange head, and a hollow barrel extending from the flange head. The hollow barrel has an internally threaded portion provided at one end of the barrel connecting to the flange head, and an enlarged flarable portion extending from the internally threaded portion and provided at a free end of the barrel. The present invention further discloses a method of forming a tee-nut with an enlarged barrel end, by first swaging out and expanding the free end of the barrel and thereafter threading the unexpanded portion of the barrel.
    Type: Grant
    Filed: September 11, 1995
    Date of Patent: April 8, 1997
    Assignee: Sigma Tool & Machine
    Inventor: Volkmar W. Leistner
  • Patent number: 5606794
    Abstract: A machine for inserting a Tee-nut into a workpiece of the type having a Tee-nut supplying source and a power cylinder assembly, the power cylinder assembly comprising a cylinder having an upper end headplate and a lower end headplate, openings provided on the cylinder for admitting and venting compressed air, a piston moveable within the cylinder, a piston rod secured to the piston, the lower end of the piston rod extending through the lower end headplate and adapted to engage and drive a Tee-nut into a workpiece, the upper end of the piston rod extending through the upper end headplate, and a kinetic energy storage unit removably mounted to the upper end of the piston rod, thereby providing a mass on the piston which is accelerated by gravity and air pressure during a downward stroke and is sufficient to drive a Tee-nut into a workpiece with a very low shock effect and to a precise depth.
    Type: Grant
    Filed: July 6, 1995
    Date of Patent: March 4, 1997
    Assignee: Sigma Tool & Machine
    Inventor: Volkmar W. Leistner
  • Patent number: 5560099
    Abstract: A machine for setting and forming a Tee-nut, of the type having a threaded sleeve and an open lower end on the sleeve, in a workpiece, and having a cylindrical body having an upper opening and a stop, a pin member slidably received within the body and having a top end die portion defining a forming surface, a first resilient device for urging the pin member in an upper normal position, and a second resilient device disposed concentrically around the pin member.
    Type: Grant
    Filed: July 20, 1994
    Date of Patent: October 1, 1996
    Assignee: Sigma Tool & Machine
    Inventors: Walter H. Leistner, Volkmar W. Leistner